ORCID Profile
0000-0002-1023-456X
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Publisher: Hindawi Limited
Date: 2014
DOI: 10.1155/2014/931264
Abstract: Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60°C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations.
Publisher: Elsevier BV
Date: 08-2008
Publisher: Elsevier BV
Date: 09-2017
Publisher: Walter de Gruyter GmbH
Date: 23-07-2008
Abstract: The effect of microwave power density on the microwave drying of red pitaya (Hylocereus costaricensis) was investigated using a small modified commercial microwave. Microwave power density was varied in the range of 5.47 to 19.02 W/g. The ambient, internal s le and s le surface temperatures, and moisture loss were measured during microwave drying at various microwave power densities. The drying rate increased with increasing power density. The temperature profiles rapidly reached their saturation level. The experimental moisture loss data were fitted to the Tang and Cenkowski drying model using a value of residual sum of squares (RSS) to evaluate the goodness of fitting the model. The dried product was analysed to examine the quality such as color, shrinkage, tensile hardness and structure. The results showed that the color change is higher at higher power density and temperature because of the faster browning rate and faster drying rate. The beginning of the color change corresponded closely to the beginning of the falling rate period. The microwave drying also caused the red pitaya to shrink to a greater extent of up to 70% at higher power density because of the faster drying rate. The internal structure also tended to collapse during microwave drying.
Publisher: Elsevier BV
Date: 10-2008
Publisher: Elsevier BV
Date: 03-2019
Publisher: Elsevier BV
Date: 08-2010
Publisher: Elsevier BV
Date: 06-2018
Publisher: Elsevier BV
Date: 2007
Publisher: Hindawi Limited
Date: 12-05-2020
DOI: 10.1002/ER.5466
Publisher: IEEE
Date: 06-2011
Publisher: Springer Science and Business Media LLC
Date: 14-05-2019
Publisher: Springer Science and Business Media LLC
Date: 19-10-2018
Publisher: Elsevier BV
Date: 10-2000
Publisher: Elsevier BV
Date: 08-2018
Publisher: Science Publications
Date: 04-2012
Publisher: Elsevier BV
Date: 2020
Publisher: Institution of Engineering and Technology
Date: 2014
DOI: 10.1049/CP.2014.1462
Publisher: Elsevier BV
Date: 05-2010
Publisher: Elsevier BV
Date: 09-2015
Publisher: IIUM Press
Date: 06-2018
DOI: 10.31436/IIUMEJ.V19I1.808
Abstract: Cu-Zn-V-Al oxide composite catalysts were prepared using a co-precipitation method to investigate hydrogen and carbon monoxide yield of a methanol reforming reaction. The mass compositions of metals were initially determined on the Simplex Centroid statistical design. The effects of various metal compositions on the physicochemical properties of the catalyst were studied via X-ray diffractogram (XRD), temperature-programmed reduction (TPR) analyses, and reaction. XRD revealed crystals in the s les. Crystalline CuO in Cu30V30Al40 formed with the addition of zinc oxide at the metal loading below 30 wt%. A combination of zinc oxide and vanadia, however, had no Zn-V complex crystal but its scanning electron microscopy image showed the formation of string structures (AS). The catalyst that contained the AS exhibited a broad hydrogen reduction peak in the TPR analysis. Vanadium at a loading below 40 wt% with various zinc and cuprum compositions also formed small ASs and exhibited single TPR peaks. A reaction yield study revealed the optimum compositions of metal oxides when the data was fitted by response surface plots. The catalysts with high content of AS were not at the peaks however. Cu-Zn based catalysts showed the highest hydrogen yield for the reaction temperature of between 150 oC to 225 oC and vanadia-promoted catalyst with AS only appeared to be the optimum catalyst at the higher temperature. ABSTRAK: Mangkin komposit oksida Cu-Zn-V-Al disediakan menggunakan kaedah pemendakan bersama untuk mengkaji hasil hidrogen dan karbon monoksida daripada tindak balas pembentukan semula metanol. Komposisi jisim logam-logam dikenal pasti terlebih dahulu menggunakan reka bentuk statistik Simplex Centroid. Pelbagai kesan komposisi logam terhadap sifat-sifat mangkin kimia-fizikal dikaji menerusi analisis-analisis pembelauan sinar-X (XRD) dan program penurunan suhu teratur (TPR), dan tindak balas kimia. Hasil analisis XRD menzahirkan kristal pada s el-s el. Hablur CuO terbentuk dalam Cu30V30Al40 dengan penambahan zink oksida pada muatan logam kurang daripada 30% berat. Gabungan zink oksida dan vanadia walau bagaimanapun tidak menghasilkan hablur kompleks Zn-V, namun imbasan imej mikroskop elektron menunjukkan pembentukan struktur tetali (AS). Mangkin yang mengandungi AS menunjukkan penurunan puncak hidrogen yang lebar dalam analisis TPR. Vanadium pada muatan berat logam kurang daripada 40% berbanding komposisi zink dan kuprum juga membentuk AS kecil dan menghasilkan puncak-puncak TPR tunggal. Hasil tindak balas kajian menunjukkan komposisi optimum oksida logam apabila data ujikaji dipadankan dengan menggunakan plot permukaan respon. Mangkin yang mempunyai kandungan AS tertinggi bagaimanapun tidak berada pada puncak. Mangkin berasaskan Cu-Zn menunjukkan hasil hidrogen tertinggi bagi suhu tindak balas antara 150 oC hingga 225 oC dan mangkin yang ditambah vanadia bersama AS pula muncul sebagai mangkin optimum pada suhu lebih tinggi.
Publisher: Science Alert
Date: 15-03-2009
Publisher: Informa UK Limited
Date: 25-02-2010
Publisher: Elsevier BV
Date: 11-2017
Publisher: Trans Tech Publications, Ltd.
Date: 28-03-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMM.52-54.1544
Abstract: In recent years, one dimensional nanostructure, nanofibers with unique properties have been subjected of intense research due to potential properties in many applications. This study presents synthesize of Perovskite-type Ba0.5Sr0.5Co0.2Fe0.8O3−δ (BSCF) nanofibers using sol-gel via electrospinning as a cathode for intermediate temperature solid oxide fuel cell. BSCF nanofibers are prepared by treating electrospun polyvinyl Pyrrolidon/ Ba0.5Sr0.5Co0.8Fe0.2O3−δ composite fibers at high temperature in an air atmosphere. BSCF nanofibers were characterized by x-ray diffraction (XRD) to observe desired structure, scanning electron microscopy (SEM) to investigated the morphology of fibers, and Brunauer, Emmett and Teller (BET) for measuring the surface area. To the best of our knowledge, investigation on Ba0.5Sr0.5 Co0.2 Fe 0.8O3−δ nanofibers has not been reported up to now.
Publisher: Elsevier BV
Date: 05-2019
Publisher: Trans Tech Publications, Ltd.
Date: 02-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.471-472.792
Abstract: One-dimensional nanostructures, like nanofibers, nanobelts, nanotubes, nanorods have been regarded as a new class of nanomaterials that have been attracted as the most promising building blocks for verity applications in the last few years. As one type of important structures with intensive research efforts have been devoted to the production and investigation of the metal oxides. Metal oxide nanofibers have different potential to play an essential role in a series of application such as optics, nanoelectronics, catalysts, sensors, storage, optoelectonics, and full cell. Copper oxide nanostructures is a promising semiconductor material with potential applications in photochemical, electrochemical, electrochromic especially in water splitting, catalysts, and fabrication of photovoltaic devices. In this paper electrospinning method via sol-gel was used to fabricate copper oxide nanofibers. Copper oxide nanofibers with different morphology were synthesized by different calcinations temperature. In this paper, effective parameters such as voltage, concentration of precursor and different calcinations temperature were characterized by thermal gravimetric analysis, scanning electron microscopy (SEM), Transmission electron microscopy, x-ray diffraction(XRD), Fourier transform infrared spectroscopy (FTIR) and Brunauer Emmett and Teller (BET).
Publisher: Informa UK Limited
Date: 15-03-2012
Publisher: Elsevier BV
Date: 07-2013
Publisher: Elsevier BV
Date: 08-2015
DOI: 10.1016/J.BIORTECH.2015.04.084
Abstract: The cathode reaction is one of the most important limiting factors in bioelectrochemical systems even with precious metal catalysts. Since aerobic bacteria have a much higher affinity for oxygen than any known abiotic cathode catalysts, the performance of a microbial fuel cell can be improved through the use of electrochemically-active oxygen-reducing bacteria acting as the cathode catalyst. These consume electrons available from the electrode to reduce the electron acceptors present, probably conserving energy for growth. Anaerobic bacteria reduce protons to hydrogen in microbial electrolysis cells (MECs). These aerobic and anaerobic bacterial activities resemble those catalyzing microbially-influenced corrosion (MIC). Sulfate-reducing bacteria and homoacetogens have been identified in MEC biocathodes. For sustainable operation, microbes in a biocathode should conserve energy during such electron-consuming reactions probably by similar mechanisms as those occurring in MIC. A novel hypothesis is proposed here which explains how energy can be conserved by microbes in MEC biocathodes.
Publisher: Elsevier BV
Date: 09-2013
Publisher: Wiley
Date: 11-2010
DOI: 10.1002/APJ.411
Publisher: International Union of Crystallography (IUCr)
Date: 18-06-2011
Publisher: Science Publications
Date: 04-2012
Publisher: Elsevier BV
Date: 09-2006
Publisher: Wiley
Date: 12-2004
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 28-04-2019
Publisher: Wiley
Date: 06-1986
Publisher: Elsevier BV
Date: 10-2018
Publisher: Elsevier BV
Date: 04-2006
Publisher: Elsevier BV
Date: 04-2006
Publisher: Elsevier BV
Date: 04-2018
Publisher: MDPI AG
Date: 22-07-2018
DOI: 10.3390/EN11071910
Abstract: The potential for using O-methylene phosphonic κ-carrageenan (OMPk) as a filler in the chitosan-based polymer electrolyte N-methylene phosphonic chitosan (NMPC) was investigated. OMPk, a derivative of κ-carrageenan, was synthesized via phosphorylation and characterized using infrared spectroscopy (IR) and nuclear magnetic resonance (NMR). Both the IR and NMR results confirmed the phosphorylation of the parent carrageenan. The solid polymer electrolyte (SPE)-based NMPC was prepared by solution casting with different weight percentages of OMPk ranging from 2 to 8 wt %. The tensile strength of the polymer membrane increased from 18.02 to 38.95 MPa as the amount of OMPk increased to 6 wt %. However, the increase in the ionic conductivity did not match the increase in the tensile strength. The highest ionic conductivity was achieved with 4 wt % OMPk, which resulted in 1.43 × 10−5 Scm−1. The κ-carrageenan-based OMPk filler strengthened the SPE while maintaining an acceptable level of ionic conductivity.
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 10-08-2016
Publisher: InTech
Date: 19-04-2011
DOI: 10.5772/15342
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 10-08-2016
Publisher: Hindawi Limited
Date: 2014
DOI: 10.1155/2014/547604
Abstract: PtRu catalyst is a promising anodic catalyst for direct methanol fuel cells (DMFCs) but the slow reaction kinetics reduce the performance of DMFCs. Therefore, this study attempts to improve the performance of PtRu catalysts by adding nickel (Ni) and iron (Fe). Multiwalled carbon nanotubes (MWCNTs) are used to increase the active area of the catalyst and to improve the catalyst performance. Electrochemical analysis techniques, such as energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS), are used to characterize the kinetic parameters of the hybrid catalyst. Cyclic voltammetry (CV) is used to investigate the effects of adding Fe and Ni to the catalyst on the reaction kinetics. Additionally, chrono erometry (CA) tests were conducted to study the long-term performance of the catalyst for catalyzing the methanol oxidation reaction (MOR). The binding energies of the reactants and products are compared to determine the kinetics and potential surface energy for methanol oxidation. The FESEM analysis results indicate that well-dispersed nanoscale (2–5 nm) PtRu particles are formed on the MWCNTs. Finally, PtRuFeNi/MWCNT improves the reaction kinetics of anode catalysts for DMFCs and obtains a mass current of 31 A g −1 catalyst.
Publisher: Elsevier BV
Date: 06-2018
Publisher: Elsevier BV
Date: 05-2013
Publisher: Trans Tech Publications, Ltd.
Date: 09-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.447-448.666
Abstract: Composite electrolytes made of samarium-doped cerium (SDC, Ce0.8Sm0.2O1.9) and (67 mol% Li/ 33mol% Na)2CO3 carbonate salts were investigated in relation to their structure, morphology and porosity of the electrolyte. The fabrication of the SDC–(Li/Na)2CO3 composite electrolytes were achieved in two steps: step (1) preparation of the samarium-doped cerium powders by sol-gel step (2) mixing of the samarium-doped cerium with carbonates in various compositions by solid state reaction. The electrolyte pellets were compacted at different pressures (25 and 50 MPa) and sintered at 600oC, 700oC and 800oC. The XRD results demonstrated that the introduction of carbonates did not change the SDC phase structure. FESEM images showed that the carbonate component was amorphous and well distributed in the SDC. The lowest porosity (2.92%) was achieved for s les with carbonate content of 30% (SDC7030) sintered at 800oC and cold pressed at 50MPa.
Publisher: Trans Tech Publications, Ltd.
Date: 05-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.233-235.17
Abstract: Catalysis is the major process involved in fuel cell technology to generate electricity which is known renewable. Generally, fuel cell electrodes utilize platinum supported carbon to catalyze the reactions at both cathode and anode. However, cheaper substitution materials such as nitrogen-doped carbon catalyst have attracted greater attention in recent year due to its significant catalytic activity at cathode in fuel cell. Nitrogen-doped CNT (N-CNT) is believed to allow oxygen reduction reaction (ORR) at cathode to take place which play a role as n-type dopant for electrical conductivity. The objective of this paper is to understand the mechanism of oxygen adsorption on N-CNT using the density-functional theory (DFT). N-CNT with two configurations involve sp 2 and sp 3 hybridized nitrogen are studied and compared in order to find the most thermodynamically stable N-CNT for sustainable ORR activity in fuel cell. The structural stability is studied through the binding energies of each configurations and the metallic behavior is examined through the energy gaps from the HOMO-LUMO studies. Finally, the adsorption energies and deformation energies of oxygen on N-CNT is discussed. Results revealed that sp 3 hybridized N-CNT gives the most stable structure with compatible oxygen adsorption ability.
Publisher: Elsevier BV
Date: 07-2013
Publisher: Elsevier BV
Date: 10-2018
Publisher: Hindawi Limited
Date: 23-07-2014
DOI: 10.1002/ER.3082
Publisher: Elsevier BV
Date: 12-2011
Publisher: Elsevier BV
Date: 05-2015
Publisher: Elsevier BV
Date: 05-2013
Publisher: Elsevier BV
Date: 11-2011
Publisher: Trans Tech Publications, Ltd.
Date: 28-03-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMM.52-54.488
Abstract: Composite anodes made of NiO and SDC-(Li/Na)2CO3 were investigated in relation to their structure, morphology, and porosity. As a first step, the anode powder was prepared by mixing the NiO with SDC-(Li/Na)2CO3 via solid state reaction in weight percentage of 60 : 40 wt% and in various compositions of carbonates (20 and 30wt%), namely NiO-SDC8020 and NiO-SDC7030, respectively. The powder mixtures were then calcined at 680oC. The resultant powder was fine with surface area of about 13.10-13.70 m2/g and an average particle size of 0.32-0.37µm. The powders consist of two phases i.e. the cubic NiO and face-centered cubic structure SDC-(Li/Na)2CO3 as confirmed with x-ray diffraction. The microstructures were observed under scanning electron microscopy (SEM). The anode pellets were later compacted at different pressures (27, 32 and 37 MPa) and sintered at 600oC. The optimum porosity (20.99-24.78%) was achieved for s les of NiO-SDC8020 and NiO-SDC7030 sintered at 600oC and cold pressed at 32 and 37 MPa.
Publisher: Trans Tech Publications, Ltd.
Date: 09-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.447-448.559
Abstract: Flow field design has several functions that should perform simultaneously. Therefore, specific plate materials and channel designs are needed to enhance the performance of proton exchange membrane (PEM) fuel cell. Serpentine flow field design is one of the most popular channel configurations for PEM fuel cell system. Some configurations have been developed to improve the cell performance. This paper presents a review on serpentine flow field (SFF) design and its influence to PEM fuel cell performance based on some indicators of performance. The comparisons of SFF with other flow field designs are summarized. The results of some experimental and numerical investigations are also presented.
Publisher: Elsevier BV
Date: 2001
Publisher: Elsevier BV
Date: 11-2013
Publisher: Elsevier BV
Date: 02-2011
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 10-08-2016
Publisher: IOP Publishing
Date: 11-2016
Publisher: Elsevier BV
Date: 08-2017
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 10-08-2016
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 10-08-2016
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 10-08-2016
Publisher: Elsevier BV
Date: 08-2010
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 28-04-2019
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 03-2012
Publisher: Trans Tech Publications, Ltd.
Date: 28-03-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMM.52-54.1884
Abstract: Metal and Metal oxide nanofibers have different potential to play an essential role in a series of application, among them copper and copper oxide nanostructures is a promising semiconductor material with potential applications in many field. In this paper, electrospinning method via sol-gel was used to fabricate copper and copper oxide nanofibers. Synthesize of copper and copper oxide nanofibers and also effect of calcinations temperature on morphology investigated by thermal gravimetric analysis, scanning electron microscopy (SEM), Transmission electron microscopy, x-ray diffraction(XRD), Fourier transform infrared spectroscopy (FTIR) and Brunauer Emmett and Teller (BET).
Publisher: AIP
Date: 2012
DOI: 10.1063/1.4732489
Publisher: International Union of Crystallography (IUCr)
Date: 09-07-2011
Publisher: Elsevier BV
Date: 10-2017
Publisher: Informa UK Limited
Date: 30-01-2009
Publisher: Trans Tech Publications, Ltd.
Date: 09-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.447-448.554
Abstract: One important aspect to develop fuel cell design is to use the concept of computational models. Mathematical modeling can be used to help research complex, estimates the optimal performance of fuel cells stack, compare several different processes, save costs and time in the investigation. This paper focuses on several reviews of research models to develop the system design of the Proton Exchange Membrane Fuel Cell (PEMFC). Purposes of this study are to determine the factors that affect system performance include: stack of PEMFC system, water management system and Supply of reactants to the PEMFC stack.
Publisher: Elsevier BV
Date: 12-2015
Publisher: Elsevier BV
Date: 07-2013
Publisher: Elsevier BV
Date: 07-2013
Publisher: Elsevier BV
Date: 09-2009
Publisher: Elsevier BV
Date: 04-2011
Publisher: Elsevier BV
Date: 02-2013
Publisher: Elsevier BV
Date: 11-2018
Publisher: Informa UK Limited
Date: 28-12-2007
Publisher: Elsevier BV
Date: 03-2013
Publisher: Elsevier BV
Date: 02-2012
Publisher: Elsevier BV
Date: 08-2016
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 07-2016
Publisher: MDPI AG
Date: 26-10-2022
DOI: 10.3390/EN15217960
Abstract: A low-performance fuel cell significantly hinders the application and commercialization of fuel cell technology. Computational fluid dynamics modeling could predict and evaluate the performance of a proton exchange membrane fuel cell (PEMFC) with less time consumption and cost-effectiveness. PEMFC performance is influenced by the distribution of reactants, water, heat, and current density. An uneven distribution of reactants leads to the localization of current density that produces heat and water, which are the by-products of the reaction to be concentrated at the location. The simplification of model geometry can affect performance prediction. Numerical investigations are commonly validated with experimental results to validate the method’s accuracy. Poor prediction of PEMFC results has not been discussed. Thus, this study aims to predict the effect of geometry modeling on fuel cell performance. Two contrasting 3D model dimensions, particularly single-channel and small-scale seven-channel models were employed. Both 3D models are correlated with a multi-channel model to assess the effect of modeling dimension on the PEMFC performance. Similar stoichiometry and channel dimensions were imposed on each model, where theoretically, the PEMFC performance should be identical. The simulation findings showed that the single-channel model produced a higher current density per cm2. From the contours of water and current density, the single-channel model does not show flow distribution. Thus, this leads to a higher current density generation than the small-scale model. The prediction of PEMFC performance is not thorough for the single-channel model. Therefore, the prediction of PEMFC performance is adaptable in a small-scale or comprehensive flow field.
Publisher: Informa UK Limited
Date: 12-1988
Publisher: Elsevier BV
Date: 09-0004
Publisher: AIP
Date: 2012
DOI: 10.1063/1.4732478
Publisher: Elsevier BV
Date: 2012
Publisher: Springer Science and Business Media LLC
Date: 10-02-2012
DOI: 10.1007/S11274-012-1007-4
Abstract: Response surface methodology (RSM) based on central composite rotatable design was used to investigate the effects of operating variable, mainly, pH, weight of biomass, and initial lead ion concentration on the lead adsorption capacity at ambient temperature using dried cells of Lactobacillius bulgaricus. Using RSM, quadratic polynomial equation was obtained for predicting the percent of lead ion removal. Analysis of variance showed that the effects of pH and weight of dried biomass were concluded to be the key factors influencing the capacity of lead ion removal. At pH lower than 2 (high acidic condition) and in alkaline condition, there is no significant biosorption. The optimum percent of lead ion removal was found at pH of 6.78, biomass concentration of 6.58 g/l and initial lead concentration 36.22 ppm. In this condition, percent of lead ion removal was 86.21%. This study showed RSM effectiveness for modeling of biosorption process.
Publisher: Elsevier BV
Date: 02-2015
Publisher: Elsevier BV
Date: 10-2011
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 12-2014
Publisher: Elsevier BV
Date: 10-2020
Publisher: Elsevier BV
Date: 08-2001
Publisher: CRC Press
Date: 24-03-2014
DOI: 10.1201/B16696
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 31-08-2018
Publisher: Elsevier BV
Date: 12-2017
Publisher: Informa UK Limited
Date: 12-2005
Publisher: Elsevier BV
Date: 10-2009
Publisher: Wiley
Date: 19-01-2015
DOI: 10.1002/JCTB.4622
Publisher: American Chemical Society (ACS)
Date: 18-05-2009
DOI: 10.1021/CG900133T
Publisher: Elsevier BV
Date: 09-2015
Publisher: Elsevier BV
Date: 08-2009
Publisher: Informa UK Limited
Date: 05-2012
Publisher: Elsevier BV
Date: 04-2017
Publisher: Science Publications
Date: 06-2009
Publisher: Elsevier BV
Date: 07-2013
Publisher: Springer Science and Business Media LLC
Date: 07-2011
Publisher: Elsevier BV
Date: 2012
Publisher: Elsevier BV
Date: 2012
Publisher: International Union of Crystallography (IUCr)
Date: 29-04-2011
Publisher: Springer Science and Business Media LLC
Date: 06-09-2022
Publisher: Wiley
Date: 10-1995
DOI: 10.1007/BF02540996
Publisher: Trans Tech Publications, Ltd.
Date: 28-03-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMM.52-54.1153
Abstract: Flooding and membrane dehydration are phenomena that must be avoided in a proton exchange membrane fuel cell (PEMFC) operation. It needs a sufficient knowledge about water transport behaviors. Electro-osmotic drag and back diffusion are the dominant water transport mechanisms through the membrane in PEMFC. In this study, the relative humidity (RH) profile along the channel at both anode and cathode sides have been recorded. The experiment was conducted in a single cell PEMFC with single serpentine flow field design. The water content profile was strongly influenced by RH profile thus in turn influenced the electro-osmotic drag coefficient, water diffusion coefficient and back diffusion flux. The operating temperatures of cell also influence those water transport behavior. The temperature was varied at 25, 40, 50 and 60 oC, while the pressure at the anode and the cathode was fixed at 1 bar. The higher the temperature, the smaller the water contents but with higher electro-osmotic drag coefficient, water diffusion coefficient and back diffusion flux. After all, the strategy of using saturated hydrogen and dry air in this study successfully prevents flooding and membrane dehydrating in the system – that are the major problems in PEMFC operation.
Publisher: Elsevier BV
Date: 08-2013
Publisher: IEEE
Date: 12-2112
Publisher: Elsevier BV
Date: 11-2013
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 09-2015
Publisher: Walter de Gruyter GmbH
Date: 13-05-2009
Abstract: This paper numerically investigated the effect of chamber aspect ratio and operating conditions on flow stability within a short form spray dryer without the inclusion of droplet injection. Extensive analysis using different mesh configurations led to a new finding on the effect of expansion ratio on flow stability. A larger expansion ratio produces a more stable flow, which is due to the limitation of the jet fluctuation by the outlet geometry constriction. However, the flow might not be completely steady as fluctuations are magnified at higher inlet velocities, which can be explained by the confined jet feed-back mechanism. Fast Fourier Transform (FFT) analysis of the computed instantaneous velocity at selected spatial locations in the chamber revealed the effect of the chamber expansion ratio on periodicity of the flow structure. It is observed that changes in the expansion ratio primarily affect the litude of the 'noise' region in the frequency spectrum.
Publisher: Informa UK Limited
Date: 11-09-2008
Publisher: Informa UK Limited
Date: 10-2007
Publisher: Elsevier BV
Date: 11-2004
Publisher: Elsevier BV
Date: 04-2009
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.BIORTECH.2015.06.105
Abstract: Microbial electrochemical technologies (METs) are emerging green processes producing useful products from renewable sources without causing environmental pollution and treating wastes. The separator, an important part of METs that greatly affects the latter's performance, is commonly made of Nafion proton exchange membrane (PEM). However, many problems have been identified associated with the Nafion PEM such as high cost of membrane, significant oxygen and substrate crossovers, and transport of cations other than protons protons and biofouling. A variety of materials have been offered as alternative separators such as ion-exchange membranes, salt bridges, glass fibers, composite membranes and porous materials. It has been claimed that low cost porous materials perform better than PEM. These include J-cloth, nylon filter, glass fiber mat, non-woven cloth, earthen pot and ceramics that enable non-ion selective charge transfer. This paper provides an up-to-date review on porous separators and plots directions for future studies.
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 03-2014
Publisher: Elsevier BV
Date: 08-2018
Publisher: Elsevier BV
Date: 07-2013
Publisher: Elsevier BV
Date: 05-2014
Publisher: Informa UK Limited
Date: 18-08-2009
Publisher: Oxford University Press (OUP)
Date: 06-2009
DOI: 10.1093/IJLCT/CTP016
Publisher: Elsevier BV
Date: 02-2019
Publisher: Penerbit UTM Press
Date: 21-06-2016
DOI: 10.11113/JT.V78.9149
Abstract: Recent advances in research and manufacturing techniques of natural fiber based composites have allowed the manufacturers to use natural fiber based composites in various applications. Natural fiber based composites are fast emerging as viable alternative to traditional materials due to their unique properties. This paper discusses the development of new natural fiber hybrid composites using mengkuang and silk fibre to achieve a unique natural fiber composites. The effects of hybridization between woven mengkuang / natural silk fiber on mode II delamination (GIIC) of laminated composites were investigated by performing the End-Notched Flexure (ENF) test. The composite s les were prepared using hand lay-up method with compression machine. After fabrication, the test specimens were subjected to ENF testing for mode II delamination based on ASTM D790-03 standards. The additional of natural silk fiber in composites fabrication provided an excellent improvement in the rate of critical strain energy release, GIIC. The Scanning Electronic Microscope (SEM) images show the delamination behaviour of the s les after failure is based on the arrangement of mengkuang and silk fibre.
Publisher: Elsevier BV
Date: 06-2010
Publisher: Elsevier BV
Date: 05-2016
Publisher: Informa UK Limited
Date: 27-05-2020
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 03-2009
Publisher: Elsevier BV
Date: 12-2014
DOI: 10.1016/J.CARBPOL.2014.07.072
Abstract: A novel nano-bio composite polypyrrole (PPy)/kappa-carrageenan(KC) was fabricated and characterized for application as a cathode catalyst in a microbial fuel cell (MFC). High resolution SEM and TEM verified the bud-like shape and uniform distribution of the PPy in the KC matrix. X-ray diffraction (XRD) has approved the amorphous structure of the PPy/KC as well. The PPy/KC nano-bio composites were then studied as an electrode material, due to their oxygen reduction reaction (ORR) ability as the cathode catalyst in the MFC and the results were compared with platinum (Pt) as the most common cathode catalyst. The produced power density of the PPy/KC was 72.1 mW/m(2) while it was 46.8 mW/m(2) and 28.8 mW/m(2) for KC and PPy in idually. The efficiency of the PPy/KC electrode system is slightly lower than a Pt electrode (79.9 mW/m(2)) but due to the high cost of Pt electrodes, the PPy/KC electrode system has potential to be an alternative electrode system for MFCs.
Publisher: Trans Tech Publications, Ltd.
Date: 12-2014
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.860-863.803
Abstract: A erse sulfonated polybenzimidazole copolymer (SPBI) as proton exchange membrane was synthesiszed via one-step high temperature polymerization method with 3,3-diaminobenzidine (DABD), 5-sulfoisophthalic acid (SIPA), 4,4-sulfonyldibenzoic acid (SDBA) and biphenyl-4,4-dicarboxylic acid (BDCA). The SPBI membrane was prepared through a direct hot-casting and in situ phase inversion technique. Characterization tests were carried out on the membranes including surface morphology, distribution of elements on the membrane, determination of functional groups, thermal stability, ion exchange capacity, water uptake rate and proton conductivity. The as-synthesized SPBI membrane displayed a smooth surface via scanning electron microscopy (SEM) analysis which is thermally stable up to 443 °C. The SPBI membrane showed higher water uptake rate (WUR) and proton conductivity though it had lower ion exchange capacity (IEC) value compared to recast Nafion membrane. The proton conductivity of the SPBI membrane with IEC of 0.60 mmol/g was 4.50 × 10 -2 S/cm at 90 °C. This study shows that the SPBI membrane has great potential in polymer exchange membrane fuel cell (PEMFC) applications.
Publisher: Elsevier BV
Date: 02-2016
Publisher: Elsevier BV
Date: 2014
Publisher: Elsevier BV
Date: 06-2018
Publisher: Wiley
Date: 28-09-2011
Publisher: Elsevier BV
Date: 12-2015
Publisher: Penerbit UTM Press
Date: 18-04-2016
DOI: 10.11113/JT.V78.8341
Abstract: Glycerol is a byproduct of biodiesel industry that has high economic value to produce hydrogen as an energy source. The selection of catalyst support for active metal catalyst in hydrogen production is a major concern since it affects the activity of metal catalyst during the steam reforming process of glycerol. Besides that, bio-based material as catalyst support provides attractive choice as it is more environmentally friendly. In this study, hydroxyapatite (HAP) as support material for tri-metallic catalyst Ni-Ce-Cu was prepared using deposition-precipitation method and used in steam reforming reaction of glycerol to produce hydrogen. The catalyst prepared was characterized by BET, FE-SEM, EDX, and TEM. The catalytic activity tests were conducted at atmospheric pressure and temperatures between 400 – 600 oC in a tubular micro-reactor. Glycerol-water ratios used were 1:4, 1:8, and 1:16. It was found that the highest hydrogen yield (55.0%) was obtained at temperature of 600 oC and glycerol-water ratio of 1: 8 with glycerol conversion of 94.0%.
Publisher: Elsevier BV
Date: 07-2013
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 10-2018
Publisher: Public Library of Science (PLoS)
Date: 28-09-2017
Publisher: Elsevier BV
Date: 2008
Publisher: Elsevier BV
Date: 10-2012
Publisher: Penerbit UTHM
Date: 15-08-2019
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 30-11-2020
DOI: 10.17576/JKUKM-2020-32(4)-05
Abstract: Metallic bipolar plates tendency to have high contact resistance and corrosion after several times of usage affected performance of a cell in PEMFC stack. This study focused on the interfacial contact resistance (ICR) and corrosion resistance of SUS 316 L bipolar plates using Cr‒C and Nb‒C as coating layer, single stack performance in PEMFC were observed by experimental. The Cr‒C and Nb‒C coating layer acted as protective layer between SUS 316 L bipolar plates. Therefore, coating is a method in preventing the bipolar plates surface material from damage in the acidic environment of PEMFC. To develop corrosion-resistant and high conductivity bipolar plates for PEMFC, the coatings bipolar plates were applied to cell fabrication in comparison with bare SUS 316 L bipolar plates. The SUS 316 L bipolar plates size and electrode area were 50 mm2 and 25 mm2, respectively. The experiment was carried out on a prepared assembled single cell bipolar plates with the commercial membranes, conductive carbon papers and gasket. Initial performance of the single cells using Cr‒C and Nb‒C coatings over SUS 316 L bipolar plates were recorded at a cell voltage between 0.4 to 0.5 V, respectively. In comparison, Nb‒C gives good performance of corrosion resistance and the ICR value as low as 10‒12 A/cm2 and 1.22 mΩ cm−2. Additionally, it gives maximum power density of 137 mW/cm2 at the cell voltage 0.51 V. The lifetime durability of the single cell significantly improved from the uncoated current density of 390 mA/cm2 to 450 mA/cm2 with Nb‒C coating layer.
Publisher: Elsevier BV
Date: 04-2013
Publisher: Wiley
Date: 02-2010
Publisher: Elsevier BV
Date: 08-2015
Publisher: Elsevier BV
Date: 2021
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 10-2018
Publisher: Elsevier BV
Date: 09-2011
Publisher: Trans Tech Publications, Ltd.
Date: 02-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.471-472.1184
Abstract: Electrospun Poly (vinylidene fluoride) (PVdF) fine fiber of 100-300 nm in diameter in ribbon shape was synthesized through the electrospinning process via sol-gel. In order to synthesize infusible nanofibers all processing of dehydrofluorination and carbonization was investigated. Iron nanoparticles was doped with PVDF nanofibers in order to be effective in surface area, and porosity to increase the hydrogen storage. The composition, morphology, structure and surface area of PVDF/Iron Oxide nanofibers were investigated by thermo gravimetric analysis (TGA) to determinate the temperature of possible decomposition and crystallinity, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Micromeritics (ASAP2020) used to study the textural properties of the s le, like surface area, total pore volume, and micro pore volume. The result shows that the PVDF without dehydrofluorination treatment for infusibility become melt at around 160 °C. By adding the iron oxide nanoparticles as a catalyst it can improve the characteristic of the carbon fiber for hydrogen storage. In best of our knowledge, PVDF doping with iron oxide investigated for first time.
Publisher: Elsevier BV
Date: 2023
DOI: 10.1016/J.SCITOTENV.2022.158527
Abstract: Microbial electrodialysis cells (MEDCs) offer simultaneous wastewater treatment, water desalination, and hydrogen production. In a conventional design of MEDCs, the overall performance is retarded by the accumulation of protons on the anode due to the integration of an anion exchange membrane (AEM). The accumulation of protons reduces the anolyte pH to become acidic, affecting the microbial viability and thus limiting the charge carrier needed for the cathodic reaction. This study has modified the conventional MEDC with an internal proton migration pathway, known as the internal proton migration pathway-MEDC (IP-MEDC). Simulation tests under abiotic conditions demonstrated that the pH changes in the anolyte and catholyte of IP-MEDC were smaller than the pH changes in the anolyte and catholyte without the proton pathways. Under biotic conditions, the performance of the IP-MEDC agreed well with the simulation test, showing a significantly higher chemical oxygen demand (COD) removal rate, desalination rate, and hydrogen production than without the migration pathway. This result is supported by the lowest charge transfer resistance shown by EIS analysis and the abundance of microbes on the bioanode through field emission scanning electron microscopy (FESEM) observation. However, hydrogen production was diminished in the second-fed batch cycle, presumably due to the active diffusion of high Cl¯ concentrations from desalination to the anode chamber, which was detrimental to microbial growth. Enlarging the anode volume by threefold improved the COD removal rate and hydrogen production rate by 1.7- and 3.4-fold, respectively, owing to the dilution effect of Cl¯ in the anode. This implied that the dilution effect satisfies both the microbial viability and conductivity. This study also suggests that the anolyte and catholyte replacement frequencies can be reduced, typically at a prolonged hydraulic retention time, thus minimizing the operating cost (e.g., solution pumping). The use of a high concentration of NaCl (35 g L
Publisher: Elsevier BV
Date: 12-2004
Publisher: Elsevier BV
Date: 07-2013
Publisher: Institution of Engineering and Technology
Date: 2014
DOI: 10.1049/CP.2014.1516
Publisher: National Library of Serbia
Date: 2013
Abstract: Drying characteristic of oil palm frond fibres was investigated in a fluidized bed dryer with the presence of inert particles. Sand was used as inert material. Effects of air temperature (60, 70 and 80?C), air velocity (0.79 and 0.85 m/s) and mass ratio of fibres to sand (1:0, 1:1 and 1:2) on the drying curves were investigated. The results showed that the shortest drying time was obtained with the highest air temperature, air velocity and fibres to sand mass ratio. The experimental drying data were fitted to nine existing drying models namely Lewis, Page, Modified Page, Henderson and Pabis, Logarithmic, Two-term, Two-term exponential and Wang and Singh models and a proposed new model. The goodness-of-fit was determined based on the values of r2, c2 and RMSE. The results showed that the best quality of the fit was obtained using the proposed model. The new model was also validated for the superheated steam drying of oil palm empty fruit bunch from other work.
Publisher: Trans Tech Publications, Ltd.
Date: 04-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/DDF.312-315.613
Abstract: An important recent discovery in the membrane science is the polymeric nanofiber membrane. Membranes have many applications in protein purification, wastewater treatment and fuel cells. One of the versatile technique with the ability of producing cost-effective, highly porous non-woven membranes with large surface area is electrospining. In this study the effect of TiO2 nanoparticles in membrane performance has been investigated. A PES/TiO2 nanofibers membrane has higher flux and permeability than a pristine PES membrane. Also the measurments show that the surface area of the membrane will increase by addition of TiO2 nanoparticles. Moreover, the contact angle was investigated.
Publisher: Elsevier BV
Date: 07-2009
Publisher: Elsevier BV
Date: 03-2003
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 28-02-2019
Publisher: IEEE
Date: 2009
Publisher: Elsevier BV
Date: 04-2017
Publisher: Wiley
Date: 22-04-2021
DOI: 10.1002/SIA.6950
Abstract: Surface‐modified zinc ferrite nanocomposites were successfully prepared thru ultrasonic impregnation technique by taking kapok fiber as a bio‐template. This work demonstrates a fast preparation method to produce the bio‐templated ZnFe 2 O 4 composite photocatalyst. The templating method for photocatalyst is favorable due to the benefit of a large surface area for solar harvesting activities in the photoelectrochemical (PEC) system. Comprehensive physicochemical analyses have successfully determined the unique properties of the prepared catalysts. The pure mimetic fibrous catalysts were successfully fabricated as photoelectrodes on the fluorine tin oxide substrate using electrophoretic deposition technique for PEC measurement. The ranging ratio of precursors used to prepare bio‐templated zinc ferrite catalysts shows an effect on their surface structure then influences the photocurrent density performance of PEC analysis. The ZF1 photoanode at 1:1 Zn/Fe ratio has generated the highest photocurrent density of 58 μA cm −2 at 0.7 V vs. Ag/AgCl compare to other s les in 0.5 M Na 2 SO 4 electrolyte solution under 100 mW cm −2 light irradiation. The high photocurrent density was attributed to the enhancement in light‐harvesting properties, fine surface structure, and high charge transfer properties that correlate with the composite ratio's alteration. The bio‐templated zinc ferrite photocatalysts are a promising photoanode in PEC activities.
Publisher: Elsevier BV
Date: 2007
Publisher: Elsevier BV
Date: 11-2010
Publisher: Elsevier BV
Date: 09-2015
Publisher: Wiley
Date: 15-04-2019
Publisher: Wiley
Date: 25-02-2011
Publisher: Elsevier BV
Date: 03-2012
Publisher: IOP Publishing
Date: 05-2021
DOI: 10.1088/1755-1315/765/1/012078
Abstract: This study aimed to further tune the capability of active metal exsolution onto the surface of the CO oxidative perovskite catalyst La 0.7 Ce 0.1 Co 0.3 Ni 0.1 Ti 0.6 O 3 by tuning the reducing parameter. Under same calcination temperature of 800°C, XRD analysis shown that the precursors with calcination duration of 6 hours (S 2 T 8 H 6 ) was able to achieve similar crystalline structure to those with calcination duration of 12 hours (S 2 T 8 H 12 ). In order for the active metal (CoNi) to be exsolved onto the perovskite surface, reducing parameter such as temperature and duration are deemed crucial to the reduction process. The exsolution of the active metals was observed when the s les were treated under reducing condition with varying temperatures of 550°C and 700°C and duration from 200 to 300 minutes. Through comparison with their EDX readings, S 2 T 8 H 6 treated under 700°C and 300 minutes (S 2 T 8 H 6 -R 7 H 5 ) achieved the highest weight percentage of surface Cobalt and Nickel of 3.83 and 2.81. It was clear that by tuning the temperature and duration of reduction, the exsolution of the active metals onto the surface of the perovskite could be improved resulting in better exposure and dispersion of active metals onto the surface of catalyst.
Publisher: Elsevier BV
Date: 09-2015
Publisher: Elsevier BV
Date: 08-2004
Publisher: BioResources
Date: 25-08-2016
DOI: 10.15376/BIORES.11.4.8615-8626
Abstract: Bionanocomposites from polylactic acid (PLA) filled with unmodified nanocrystalline cellulose from TEMPO-oxidized oil palm empty fruit bunch (OPEFB-NCC) at various loading levels were fabricated using the solvent casting technique. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), attenuated total reflectance Fourier transform infrared spectroscopy (ATF-FTIR), differential scanning calorimetry (DSC), and mechanical analyses were used to characterize the bionanocomposite films. FTIR suggested that the incorporation of the OPEFB-NCC was based on physical interaction. The melting temperature did not change markedly except at higher OPEFB-NCC additions, while the crystallization temperature shifted to lower temperatures and crystallinity increased with increasing OPEFB-NCC content.The SEM of cryo-fractured films indicated a rather weak compatibility between the OPEFB-NCC and PLA, resulting in the decrease of both the modulus and the tensile strength of the bionanocomposite.
Publisher: Wiley
Date: 08-10-2021
DOI: 10.1002/ESE3.988
Abstract: A proton exchange membrane (PEM) is one of the most critical and expensive components in a dual‐chamber microbial fuel cell (MFC) that separates the anode and cathode chambers. The novel macroporous kaolin earthenware coated with polybenzimidazole (NKE‐PBI) fabricated in this study could become an alternative to PEM membranes. Briefly, PBI powder was dissolved in dimethylacetamide. Thereafter, NKE was fabricated at different porosities (10%, 20%, and 30%) using different starch powder volumes, which acted as pore‐forming agents. The NKE‐PBI with 30 vol% starch powder content produced the highest power output of 2450 ± 25 mW m −2 (10.50 A m −2 ) and internal resistance of 71 ± 19 Ω under batch mode operation. The MFC–PEM reactor generated the lowest power output at the highest internal resistance of up to 1300 ± 15 mW m −2 (3.7 A m −2 ) and 313 ± 16 Ω, respectively. In this study, the nonselective porous NKE coated with PBI membranes improved proton conduction activity and displayed comparable power performance with that of Nafion 117 in a dual‐chambered MFC. Therefore, a porous earthenware membrane coated with a proton conductor could become a potential separator in a scaled‐up MFC system for commercialization.
Publisher: MDPI AG
Date: 03-12-2020
DOI: 10.3390/PR8121592
Abstract: The ever increasing energy consumption, rising public awareness for environmental protection, and higher prices of fossil fuels have motivated many to look for alternative and renewable energy sources [...]
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 12-2013
Publisher: Elsevier BV
Date: 08-2012
Publisher: Elsevier BV
Date: 10-2008
Publisher: Trans Tech Publications, Ltd.
Date: 04-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/DDF.312-315.607
Abstract: One dimensional (1D) nanostructure materials such as nanowires, nanofibers, and nanorods with porous structures have potential for use in various applications. Electrospinning is one of the versatile techniques with the ability of producing cost-effective, large production, highly porous nanofibers and membrane with large surface to volume ratios. Poly ether sulfone (PES) is a kind of special engineering plastic with good processing characteristics. In this paper, synthesis of PES membrane was investigated by two main methods, i.e. phase inversion and electrospiing. For electrospining, the main effective parameters such as concentration of polymer and solvent, for finding the optimized condition of electrospun PES membrane was studied. The produced membranes were characterized by SEM for morphology and BET observation of surface area, permeability, flux, and mechanical propertise for different applications.
Publisher: Elsevier BV
Date: 12-2014
Publisher: International Society for Horticultural Science (ISHS)
Date: 07-2011
Publisher: Springer Science and Business Media LLC
Date: 2013
DOI: 10.2478/S11696-013-0368-Y
Abstract: Hydroxyapatite-supported Ni-Ce-Cu catalysts were synthesised and tested to study their potential for use in the steam reforming of glycerol to produce hydrogen. The catalysts were prepared by the deposition-precipitation method with variable nickel, cerium, and copper loadings. The performance of the catalysts was evaluated in terms of hydrogen yield at 600°C in a tubular fixed-bed microreactor. All catalysts were characterised by the BET surface area, XRD, TPR, TEM, and FE-SEM techniques. The reaction time was 240 min in a fixed-bed reactor at 600°C and atmospheric pressure with a water-to-glycerol feed molar ratio of 8: 1. It was found that the Ni-Ce-Cu (3 mass %-7.5 mass %-7.5 mass %) hydroxyapatite-supported catalyst afforded the highest hydrogen yield (57.5 %), with a glycerol conversion rate of 97.3 %. The results indicate that Ni/Ce/Cu/hydroxyapatite has great potential as a catalyst for hydrogen production by steam reforming of glycerol.
Publisher: Informa UK Limited
Date: 02-01-2004
DOI: 10.1081/SS-120030479
Publisher: Elsevier BV
Date: 04-2009
Publisher: Elsevier BV
Date: 2016
Publisher: Trans Tech Publications, Ltd.
Date: 28-03-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMM.52-54.875
Abstract: The assembly of proton exchange membrane fuel cell (PEMFC) is the important factor for the performance. The achievement of proper design will improve the pressure distribution and the electrical contact resistance between fuel cell parts. The assembly pressure affects the contact behavior between of bipolar plate and gas diffusion layer (GDL). In this study, finite element analysis (FEA) was used to analyze the behavior of single cell fuel cell under the variation of assembly pressure. It shows 3D of deformation, and the compression pressure every part of the fuel cell components. The simulation varied the torque assembly from 1 Nm to 3 Nm with increment 0.5 Nm. The simulation using FEA shows that high assembly pressure also affects to the high deformation and stress in the components of fuel cell. This phenomenon affects to the performance of PEM fuel cell.
Publisher: Physical Society of Japan
Date: 15-09-2016
Publisher: Springer Science and Business Media LLC
Date: 19-03-2020
Publisher: Elsevier BV
Date: 05-2011
Publisher: Elsevier BV
Date: 09-2014
Publisher: Elsevier BV
Date: 03-2010
Publisher: Trans Tech Publications, Ltd.
Date: 02-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.471-472.1046
Abstract: The need and development of cleaner and greener alternative technologies using the heterogeneous catalytic system in the synthesis of fuel is very important. In this work hydrogen production via steam reforming of glycerol (C3H8O3) was carried out over nickel supported on hydroxyapatite [Ca5(PO4)3(OH)] as a biomaterial catalyst. The time reaction is carried out for 240 minutes in a fixed-bed reactor fixed at 600 oC and atmospheric pressure with the water-to-glycerol feed ratio of 8:1. Catalysts were prepared by mean of impregnation and sol-gel method with varied nickel loadings (3, 6, 9, 12 %) on hydroxyapatite. The catalysts were characterized by BET surface area, X-ray diffraction, and SEM-EDX techniques. It is found that 3 wt% of nickel loading prepared via sol-gel method exhibit the higher hydrogen production rates (63.62 % - 74.16 %) in comparison to the other nickel loadings.
Publisher: Informa UK Limited
Date: 05-2010
Publisher: Elsevier BV
Date: 2014
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 09-2015
Publisher: Trans Tech Publications, Ltd.
Date: 09-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.447-448.700
Abstract: In this work, the potential of utilizing the porous alumina ceramic membrane coated with palladium as a hydrogen permselective membrane has been studied. The ceramic membrane is characterized by high permeability but at low hydrogen selectivity. In order to increase the pure hydrogen selectivity and to obtain high hydrogen yield on the ceramic membrane, palladium was coated on the alumina membrane surface. Such an arrangement would also enable the ceramic membrane to be operated at higher temperature. The preparation of the palladium coated ceramic membrane was carried out using combine sol-gel process and the electroless plating technique. The effect of combine sol-gel process with electroless plating towards deposits morphology, hydrogen permeability, and hydrogen permselectivity were analysed. The thickness and morphology of the α- Alumina and Pd composite membranes were analysed using a scanning electron microscopy (SEM) and atomic force microscopy (AFM).
Publisher: International Union of Crystallography (IUCr)
Date: 17-09-2011
Publisher: Hindawi Limited
Date: 05-07-2014
DOI: 10.1002/ER.3223
Publisher: Trans Tech Publications, Ltd.
Date: 02-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.471-472.1040
Abstract: In recent years, one dimensional nanostructure, nanowires, nanofibers with unique properties have been a subject of intense research due to reduction of devise dimension, potential properties from the re-arrangement at the molecular level and high surface area. There are many methods for synthesize such as laser ablation, chemical vapour deposition, solution method micro pulling down method but all these method faced to the major disadvantages of being complicated with long wasting time and relatively high expense . The electrospinning recently used for producing ceramic, metal, and carbon nanofibers. In this report, we incorporate palladium into silica nanofibers for the first time, and the effect of doping of palladium into the silica nanofibers is investigated. The different ratio of palladium to silica and comparing with silica nanofibers is also reported. The composition, morphology, structure and surface area of silica, and silica palladium nanofibers were investigated by thermo gravimetric analysis (TGA), x-ray diffraction (XRD), scanning electron microscopy (SEM),Fourier transform infrared spectroscopy (FT-IR), and Micromeriics. To the best of our knowledge, investigation on characteristic on Silica palladium nanofibers has not been reported up to now. The result reveal that the silica nanofibers compare to silica doped with palladium have lower diameter, and also by increasing the temperature above 600 °C, the reduction in length of nanofibers happened. High surface area of silica palladium nanofibers can be one of the promising materials for hydrogen storage.
Publisher: Elsevier BV
Date: 09-2014
Publisher: Elsevier BV
Date: 07-2013
Publisher: Elsevier BV
Date: 02-2010
Publisher: Elsevier BV
Date: 06-2009
Publisher: Elsevier BV
Date: 10-2008
Publisher: Informa UK Limited
Date: 08-2007
Publisher: Elsevier BV
Date: 11-2006
Publisher: Elsevier BV
Date: 10-2004
Publisher: American Chemical Society (ACS)
Date: 16-04-2012
DOI: 10.1021/CG200266E
Publisher: Elsevier BV
Date: 04-2014
DOI: 10.1016/J.SAA.2013.12.107
Abstract: Bis(dithiolene) tungsten carbonyl complex, W(S2C2Ph2)2(CO)2 was successfully synthesized and the structure, frontier molecular orbital and optical properties of the complex were investigated theoretically using density functional theory calculations. The investigation started with a molecular structure construction, followed by an optimization of the structural geometry using generalized-gradient approximation (GGA) in a double numeric plus polarization (DNP) basis set at three different functional calculation approaches. Vibrational frequency analysis was used to confirm the optimized geometry of two possible conformations of [W(S2C2Ph2)2(CO)2], which showed distorted octahedral geometry. Electronic structure and optical characterization were done on the ground states. Metal to ligand and ligand to metal charge transfer were dominant in this system.
Publisher: Elsevier BV
Date: 07-2013
Publisher: Elsevier BV
Date: 2019
Publisher: Walter de Gruyter GmbH
Date: 04-04-2016
DOI: 10.3139/120.110860
Abstract: The effects of hybridization between woven mengkuang fiber/woven silk on mode II delamination (GIIC) of laminated composites were investigated by performing the end-notched flexure (ENF) test. Various configurations of woven mengkuang/woven silk layers were considered. The composite s les were prepared using hand lay-up, along with the cold press method. After fabrication, the test specimens were subjected to end-notch flexure testing for mode II delamination based on ASTM D790-03. During the test, the crack propagation was observed the sudden drop in load meant that the s le experienced crack growth. The configuration of woven silk in between the pre-crack provided an excellent improvement in G IIC . Further addition of woven silk layers for similar configuration also yielded significant improvements in the G IIC result. The rate of critical strain energy release increases with an increase in number of woven silk layers for the configuration of silk in between the pre-crack. The scanning electronic microscopy (SEM) result shows the cross-section of the s les. The study also demonstrated that surface interaction between woven silk/epoxy/woven silk was better than woven mengkuang/epoxy/woven mengkuang lamination.
Publisher: Academic Journals
Date: 23-12-2011
DOI: 10.5897/IJPS11.1458
Publisher: Elsevier BV
Date: 07-2015
Publisher: Elsevier BV
Date: 02-2012
Publisher: Elsevier BV
Date: 10-2000
Publisher: Elsevier BV
Date: 05-2020
Publisher: Penerbit UTM Press
Date: 19-07-2017
Abstract: Photoelectrochemical (PEC) water splitting is a very promising green method to produce solar fuel. Titanium dioxide (TiO2) has been widely used as photocatalyst for this type of reaction. Improving the performance of TiO2 for PEC water splitting has been ongoing and addition of sacrificial donor especially from waste is an attractive option to achieve this. Oxalic acid is one component in organic waste stream that can be used as sacrificial donor. The TiO2 thin films has been fabricated by coating TiO2 paste on Fluorine Tin oxide (FTO) glass surface. The morphology of the TiO2 thin films were porous and rough with uniform particles size with crystallite size of about 20 nm and dominant anatase peak. The TiO2 photoelectrode undergo PEC testing to measure its photolectroactivity by using oxalic acid as a sacrificial donor in two different type of electrolytes which are distilled water and sodium sulfate (NA2SO4) aqueous solution. The photocurrent produced without addition of oxalic acid is much lower than with the acid. The saturation photocurrent for aqueous NA2SO4 solution and water electrolyte is 0.1 mA/cm2 and negligible respectively. While the photocurrent for addition of oxalic acid in NA2SO4 aqueous solution is 0.5 mA/cm2 and the photocurrent for oxalic acid in water only is 0.9 mA/cm2, which is almost double compared to in NA2SO4 and tenfold in water only. The highest photocurrent produced by TiO2 photoelectrode is by addition of oxalic acid in aqueous (H2O) electrolyte.
Publisher: Informa UK Limited
Date: 06-12-2010
Publisher: Elsevier BV
Date: 05-2012
Publisher: Elsevier BV
Date: 12-2013
Publisher: IOP Publishing
Date: 06-2019
DOI: 10.1088/1755-1315/268/1/012142
Abstract: The characteristics of tar generated from tropical-plant-based biomass with different chemical compositions during high temperature gasification are crucial to understand the tar formation. In this paper, lignin-rich palm kernel shell (PKS) and hemicellulose and cellulose-rich coconut shell (CS) were gasified in a downdraft fixed-bed reactor at 900 °C. Fourier transform infrared spectroscopy (FTIR) and gas chromatography coupled with mass spectrometry (GC-MS) were used to examine the functional groups and tar compounds. The results of FT-IR indicate that the PKS tar has a lower intensity peak in the fingerprint region than that of CS. The GC-MS results exhibits that the higher molecular weight of tar compounds, such as polycyclic aromatic hydrocarbons (PAHs) are higher in CS tar compared to that in PKS tar. PKS tar is susceptible to create a lighter molecular weight of tar compounds, such as phenolics. Both of the materials have a great potential to be used for renewable energy feedstock.
Publisher: Inderscience Publishers
Date: 2020
Publisher: Elsevier BV
Date: 2018
Publisher: Elsevier BV
Date: 02-2011
Publisher: Elsevier BV
Date: 11-2019
Publisher: International Hellenic University
Date: 2022
Publisher: Elsevier BV
Date: 04-2020
Publisher: Wiley
Date: 16-02-2005
Publisher: Elsevier BV
Date: 03-2012
Publisher: Science Publications
Date: 07-2007
Publisher: Trans Tech Publications, Ltd.
Date: 05-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.233-235.43
Abstract: Electrode performance is the most important part in proton exchange membrane fuel cell system because all electrochemical processes and chemical conversions into energy occur via electrode interface. However the main problem in widespread proton exchange membrane fuel cells (PEMFCs) applications is the cost of the catalyst and life time of electrode, due to different parameters effects. Intense research imply in reducing the cost with increase the activity of catalyst in additional to other parameters (components) to make electrode for PEM more efficient with reasonable cost. This paper review recent research for the most parameters affecting performance of (Pt/C and Pt/C/M ) electrode for proton exchange membrane fuel cells (PEMFCs) such as Catalyst oxidation (degradation), and life time of the electrode using Pt/C, gas diffusion layer (GDL) thickness, and loading of PTFE in the diffusion layer, Nafion @ solution in the catalyst layer, methods of fabrication of electrode as spraying, casting, and electro deposition methods. Then the link between these parameters to achieve high performance and avoid the electrode degradation by optimized these parameters.
Publisher: Informa UK Limited
Date: 31-12-2003
Publisher: Trans Tech Publications, Ltd.
Date: 02-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.471-472.97
Abstract: Porous Ag-Bi2O3 composite cathodes on stainless steel (SS) substrate, an excellent mixed-ionic conductor that can be used as cathode material for the intermediate temperature solid oxide fuel cell (IT-SOFC) has been developed using the slurry painting method. Characterisation of the composite cathode includes the thermal analysis, morphology, and porosity of the porous cathode. Thermal analysis of the dried slurry was conducted in order to determine the heating schedule for eliminating the organic components using thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC). The TGA and DSC analyses confirmed the organic vehicle was fully decomposed below 418oC and the formation of composite cathode oxide phase took place beyond 600oC. The microstructure of the thermally treated cathode was analysed using SEM and XRD. The SEM results showed that the grain size of the cathode increased with the increase of temperature during thermal treatment and the X-ray diffraction (XRD) analyses confirmed the presence of δ-Bi2O3 phase on the cathode. Porosity was obtained using the Archimedes method. The Ag2O3-Bi2O3 cathode on stainless steel substrates was found to have a porosity of 53%, 51%, 39% and 28% upon 1, 2, 3, and 4 coatings, respectively, as well as thermal treatment at 800°C for 1 hour.
Publisher: Elsevier BV
Date: 05-2013
Publisher: Elsevier BV
Date: 06-2013
Publisher: Wiley
Date: 2007
DOI: 10.1002/APJ.53
Publisher: IOP Publishing
Date: 02-02-2018
Publisher: Informa UK Limited
Date: 11-09-2008
Publisher: International Union of Crystallography (IUCr)
Date: 09-07-2011
Publisher: Elsevier BV
Date: 07-2006
Publisher: Elsevier BV
Date: 07-2013
Publisher: IOP Publishing
Date: 24-12-2018
Publisher: Elsevier BV
Date: 12-1999
Publisher: Elsevier BV
Date: 04-2017
Publisher: Springer Science and Business Media LLC
Date: 15-02-2016
Publisher: Elsevier BV
Date: 04-2013
Publisher: Elsevier BV
Date: 2000
Publisher: Informa UK Limited
Date: 06-2007
Publisher: Elsevier BV
Date: 09-2013
Publisher: Elsevier BV
Date: 04-1996
DOI: 10.1016/0378-4347(96)00008-4
Abstract: An ethanolic extract of cloves was analyzed by gas chromatography directly to identify eugenol and other major phenolic compounds without previous separation of other components. Separation was performed on a fused-silica capillary column of 30 m x 0.53 mm I.D., 0.53 microns film thickness. The detector was a flame ionization detector. Helium gas at a flow-rate of 3 ml/min was used as a carrier gas. The analysis were performed with linear temperature programming. Nine components were detected and special attention was given to the major phenolic compound, eugenol.
Publisher: Elsevier BV
Date: 02-2014
DOI: 10.1016/J.SAA.2013.09.069
Abstract: A new homoleptic dithiolene tungsten complex, tris-{1,2-bis(3,5-dimethoxyphenyl)-1,2-ethylenodithiolene-S,S'}tungsten, was successfully synthesized via a reaction of the thiophosphate ester and sodium tungstate. The thiophosphate ester was prepared from 3,5-dimethoxybenzaldehyde via benzoin condensation to produce the intermediate 1,2-bis-(3,5-dimethoxyphenyl)-2-hydroxy-ethanone compound, followed by a reaction of the intermediate with phosphorus pentasulfide. FTIR, UV-Vis spectroscopy, 1H NMR and 13C NMR and elemental analysis confirmed the product as tris{1,2-bis-(3,5-dimethoxyphenyl)-1,2-ethylenodithiolene-S,S'}tungsten with the molecular formula of C54H54O12S6W. Crystals of the product adopted a monoclinic system with space group of P2(1)/n, where a=12.756(2) Å, b=21.560(3) Å, c=24.980(4) Å and β=103.998(3)°. Three thioester ligands were attached to the tungsten as bidentate chelates to form a distorted octahedral geometry. Density functional theory calculations were performed to investigate the molecular properties in a generalized-gradient approximation framework system using Perdew-Burke-Ernzerhof functions and a double numeric plus polarization basis set. The HOMO was concentrated on the phenyl ligands, while the LUMO was found along the W(S2C2)3 rings. The theoretical optical properties showed a slight blue shift in several low dielectric solvents. The solvatochromism effect was insignificant for high polar solvents.
Publisher: Wiley
Date: 06-08-2007
DOI: 10.1002/APJ.61
Publisher: Elsevier BV
Date: 08-2020
Publisher: Hindawi Limited
Date: 16-08-2021
DOI: 10.1002/ER.7181
Publisher: Elsevier BV
Date: 03-2010
Publisher: Elsevier BV
Date: 09-2000
Publisher: Elsevier BV
Date: 03-2016
Publisher: Trans Tech Publications, Ltd.
Date: 09-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.447-448.770
Abstract: Nickel-hydroxyapatite as biomaterial catalysts exhibited high activity and selectivity in glycerol steam reforming. The catalytic steam reforming of glycerol (C3H8O3) for the production of hydrogen is carried out over nickel supported on hydroxyapatite [Ca5(PO4)3(OH)] catalyst at 600 oC with atmospheric pressure and 120 minute time reaction. The catalysts were prepared by mean of wet impregnation method and varied nickel loadings (3, 6, 12 %) on hydroxyapatite. It is found that the 3% wt% Ni/HAP show higher hydrogen production rate over the other nickel loadings on hydroxyapatite, which is correlated with Ni/HAP catalyst surface area measured by BET adsorbtion and morphology of catalysts. Glycerol steam reforming with water-to-glycerol feed ratio 8/1 much more hydrogen production (77-82%) compared feed ratio 4/1. The catalysts were characterised by BET surface area and SEM-EDX techniques.
Publisher: IOP Publishing
Date: 03-2018
Publisher: Elsevier BV
Date: 08-2014
Publisher: Elsevier BV
Date: 08-2017
DOI: 10.1016/J.BIORTECH.2017.03.127
Abstract: The bioanode is important for a microbial electrolysis cell (MEC) and its robustness to maintain its catalytic activity affects the performance of the whole system. Bioanodes enriched at a potential of +0.2V (vs. standard hydrogen electrode) were able to sustain their oxidation activity when the anode potential was varied from -0.3 up to +1.0V. Chrono erometric test revealed that the bioanode produced peak current density of 0.36A/m
Publisher: Informa UK Limited
Date: 18-07-2019
Publisher: Elsevier BV
Date: 08-2016
Publisher: Trans Tech Publications, Ltd.
Date: 09-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.447-448.775
Abstract: Stress applying in the stack of Proton Exchange Membrane Fuel Cell (PEMFC) effects the performance of PEMFC. High pressure in the Membrane Electrode Assembly (MEA) can reduce electrical contact resistance between bipolar plate and MEA. Nevertheless, too high pressure in the PEMFC can destroy MEA. Performance of PEMFC can be optimized by make proportional stress in the assembly of PEMFC. Finite element analysis (FEA) is one of method that can be used for analysis of stress in the PEMFC stack. However, setting of parameter in the analysis using FEA still became one of problem if realistic result must be desired. This paper reports setting of parameters in the stress analysis of PEMFC assembly using FEA method and study relationship of stress analysis with electrical contact resistance.
Publisher: Elsevier BV
Date: 02-2009
Publisher: Elsevier BV
Date: 11-2015
Publisher: Elsevier BV
Date: 07-2013
Publisher: Elsevier BV
Date: 10-2020
Publisher: EDP Sciences
Date: 2018
DOI: 10.1051/MATECCONF/201815603033
Abstract: Design of the Proton Exchange Membrane (PEM) fuel cell system is still developed and improved to achieve performance and efficiency optimal. Improvement of PEM fuel cell performance can be achieved by knowing the effect of system parameters based on thermodynamics on voltage and current density. Many parameters affect the performance of PEM fuel cell, one of which is the relative humidity of the reactants that flow in on the anode and cathode sides. The results of this study show that the increase in relative humidity value on the cathode side (RHC) causes a significant increase in current density value when compared to the increase of relative humidity value on the anode side (RHA). The performance of single cells with high values is found in RHC is from 70% to 90%. The maximum current density generated at RHA is 70% and RHC is 90% with PEM operating temperature of 363 K and pressure of 1 atm
Publisher: Informa UK Limited
Date: 02-02-2015
Publisher: ASME International
Date: 13-03-2014
DOI: 10.1115/1.4026932
Abstract: The effects of the polytetrafluoroethylene (PTFE) content and sintering temperature on the properties of a fuel cell electrode backing layer are studied in this work. Characterization of the electrical conductivity, hydrophobicity, and surface structure of the backing layer is carried out for various PTFE content values (15–45 wt. %) and sintering temperatures (175–400 °C). The results showed that, generally, the electrical conductivity of the backing layer surface decreased whereas the hydrophobicity increased as the PTFE content and the sintering temperature increased. Based on the observations made via scanning electron microscope (SEM) analysis and testing of the electrical conductivity and hydrophobicity, the PTFE content should not exceed 35 wt. %, and the best sintering temperature was 350 °C.
Publisher: The Electrochemical Society
Date: 2018
DOI: 10.1149/2.0381811JES
Publisher: International Journal of Technology
Date: 24-05-2019
Publisher: Elsevier BV
Date: 1988
Publisher: Frontiers Media SA
Date: 15-08-2018
Publisher: Elsevier BV
Date: 02-2020
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 15-06-2016
Publisher: Elsevier BV
Date: 03-2016
Publisher: Elsevier BV
Date: 08-2012
Publisher: Elsevier BV
Date: 09-2008
Publisher: Elsevier BV
Date: 1999
Publisher: IEEE
Date: 11-2017
Publisher: Elsevier BV
Date: 2004
Publisher: Elsevier BV
Date: 05-2018
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 06-2013
Publisher: Elsevier BV
Date: 09-2015
Publisher: Elsevier BV
Date: 11-2019
Publisher: Wiley
Date: 2000
DOI: 10.1002/1097-4660(200009)75:9<812::AID-JCTB284>3.0.CO;2-B
Publisher: IEEE
Date: 12-2012
Publisher: ASME International
Date: 05-07-2013
DOI: 10.1115/1.4024866
Abstract: The characteristics of four new proton-conducting membranes, Nafion112 olyaniline composite membranes of various compositions, are studied for application as membrane separators in microbial fuel cells. The composite membranes are made by immersing Nafion-112 membranes in a solution containing aniline for different immersion times. The presence of polyaniline and sulfonic functional groups in the composite membranes is confirmed by means of Fourier transform infrared analysis while their surface roughness is determined by using atomic force microscopy prior to microbial fuel cell operation. Biofouling on the membranes' surface is also examined by using a scanning electron microscope after microbial fuel cell operation. The polarization curves and, hence, the power density curves are measured by varying the load's resistance. The power density of the microbial fuel cell with the Nafion olyaniline composite membranes improves significantly as the amount of polyaniline increases because the interaction between sulfonic groups in the Nafion matrix and polyaniline in the polyaniline domains increases proton conductivity. However, it declines after more polyaniline is added because of less conjugated bonding of polyaniline and sulfonic acid groups for larger polyaniline domains in the Nafion matrix. The voltage overpotential is also smaller as the amount of polyaniline increases. Biofouling also decreases with increasing polyaniline in the Nafion olyaniline composite membranes because they have smoother surfaces than Nafion membranes. The results show that the maximum power generated by the microbial fuel cells with Nafion112-polyaniline composite membrane is 124.03 mV m−2 with a current density of 454.66 mA m−2, which is approximately more than ninefold higher than that of microbial fuel cells with neat Nafion-112. It can be concluded that the power density of the microbial fuel cell can be increased by modifying the Nafion membrane separators with more conductive polymers that are less susceptible to biofouling to improve its proton conductivity.
Publisher: Hindawi Limited
Date: 03-06-2021
DOI: 10.1002/ER.6899
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 31-12-2018
Publisher: Elsevier BV
Date: 10-2017
Publisher: Walter de Gruyter GmbH
Date: 13-08-2008
Abstract: Advanced drying technology enables drying of rough rice and dedusting of rice husks to be carried out simultaneously in the same unit processor. This paper reports the efficiency of dedusting of rice husks in a two-stage inclined cross flow fluidized bed dryer and the drying kinetics of rough rice in a batch fluidized bed dryer as well as the conceptual design of a hybrid drying dedusting unit processor. Experimental works had been carried out using rough rice (a Group D particle according to Geldart classification of powders) in a 2.5 m height two-stage inclined fluidized bed column of cross sectional area of 0.61m x 0.15m and a 3 m high batch fluidized bed dryer. The objectives of the study was to investigate the separation efficiency of dedusting of rice husks in the two-stage cross flow fluidized bed dryer and to study the drying kinetics of rough rice drying in the batch fluidized bed dryer. The experimental results showed that the dedusting separation efficiency at low superficial gas velocity gave unsatisfactory separation of merely 40% of rice husks. At higher superficial gas velocity, separation efficiency of rice husks as high as 93% was achieved. In addition, higher distributor inclination angle gave slightly improved separation efficiency. The drying kinetics showed that the residence time that is required to reduce the moisture content of rough rice to 18% (intermediate storage moisture content for second stage drying) is 3 minutes whereas the residence time that is required to reduce the moisture content to 13% (desirable final moisture content) is approximately 10 minutes regardless of the effect of kernel cracking. It was also found that higher drying temperatures gave higher drying rate. A conceptual design has been developed based on the results obtained in the studies. In order to maximize the heat utilization and to carry out two processes viz. dedusting and drying in one unit processor, it is suggested that drying dedusting can be carried out in a multistage mode where drying is taken place at each stage while dedusting is taking place at the upper stage. This concept can be applied to a packed bed or a fluidized bed unit processor.
Publisher: Elsevier BV
Date: 04-2013
Publisher: Springer Science and Business Media LLC
Date: 25-06-2022
Publisher: Elsevier BV
Date: 10-2014
Publisher: Elsevier BV
Date: 08-2009
Publisher: American Society of Civil Engineers (ASCE)
Date: 03-2007
Publisher: Elsevier BV
Date: 06-2021
Publisher: Springer Science and Business Media LLC
Date: 19-06-2009
Publisher: Elsevier BV
Date: 12-2016
Publisher: Wiley
Date: 13-03-2009
Publisher: Elsevier BV
Date: 08-2015
Publisher: Elsevier BV
Date: 11-2019
Publisher: Trans Tech Publications, Ltd.
Date: 10-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.139-141.141
Abstract: Solid oxide fuel cells (SOFCs) have been the centre of much research attention as these shows much potential in the generation of electrical power especially in terms of the high conversion efficiency of chemical energy to electric power. Recent research has been focused on a new material which is an electro catalyst for the oxygen reduction reaction in the intermediate temperature range (600-800oC). In this work, perovskite oxide which is a mixed ionic conducting material, La1-xSrxCo0.2Fe0.8O3-δ (LSCF) with x = 0.3-0.5 has been developed using the sol-gel method. The obtained powders were pelletized and sintered at different temperatures from 800 to1300oC. The sintered properties of the LSCF pellets such as density, porosity, grain size and shrinkage were investigated. A sintering temperature of 900oC was found to be the optimum temperature for the preparation of the LSCF cathodes in this study.
Publisher: Elsevier BV
Date: 08-2009
Publisher: Elsevier BV
Date: 04-2010
Publisher: Penerbit UTM Press
Date: 29-12-2016
DOI: 10.11113/JT.V79.7344
Abstract: Mass commercialization of fuel cells (FC) and its usage in transportation requires that the FC technology to be competitive with regard to performance and cost, while meeting efficiency and emissions targets. Therefore, fuel cell output current ripple that may shorten FC lifespan, worsen FC efficiency and reduce the FC output capacity need to be addressed. In this paper, an improved multi-device interleaved boost converter (MDIBC) with novel multiplex controller topology is designed to further reduce the input current and output voltage ripples, without increasing the number of MDIBC switching devices. The Matlab/Simulink behaviour model of the improved MDIBC with novel multiplex controller and conventional MDIBC circuit are developed in the simulation studies. The proposed improved MDIBC design is then compared with the conventional MDIBC and its performance is verified.
Publisher: Trans Tech Publications, Ltd.
Date: 05-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.233-235.2299
Abstract: Due to similar publication in another journal the authors have withdrawn the paper.
Publisher: Elsevier BV
Date: 04-2017
Publisher: Science Alert
Date: 15-06-2011
Publisher: Elsevier BV
Date: 03-2014
Publisher: IOP Publishing
Date: 24-12-2018
Publisher: Elsevier BV
Date: 2017
Publisher: Trans Tech Publications, Ltd.
Date: 02-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.471-472.179
Abstract: Composite cathodes made of perovskite La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) and SDC carbonates (SDC-(Li/Na)2CO3) were investigated in relation to their structure, morphology, thermal expansion coefficient and porosity. As a first step, the LSCF powder was prepared by sol-gel technique. This was followed by the preparation of the LSCF-SDC carbonates composite cathode by mixing the LSCF with SDC-(Li/Na)2CO3 electrolyte via solid state reaction in various compositions, i.e. 30, 40 and 50 wt.%, namely 70LSCF-30SDC7030, 60LSCF-40SDC7030 and 50LSCF-50SDC7030, respectively. The powder mixtures were then calcined at 680oC. The resultant powder was fine with surface area of about 3.39-7.42 m2/g and particle size of 0.56-0.66µm. The powder consists of two distinct phases, i.e. LSCF and SDC-(Li/Na)2CO3 as confirmed with x-ray diffraction. The microstructures were observed under scanning electron microscopy (SEM). Increasing the amount of the SDC-(Li/Na)2CO3 electrolyte in the composite cathode was found to bring the thermal expansion of the cathode closer to that of the electrolyte. The cathode pellets were later compacted at different pressures (27, 32 and 37 MPa) and sintered at 600oC. The optimum porosity (20.99-24.98%) was achieved for s les with SDC-(Li/Na)2CO3 content of 30-50% sintered at 600oC and cold pressed at 37 MPa.
Publisher: Elsevier BV
Date: 03-2009
Publisher: Walter de Gruyter GmbH
Date: 23-10-2007
Abstract: Several parameters related to the physicochemical properties of Josapine pineapple juice, such as moisture content, total soluble solids (TSS), pH, color, water activity, freezing point, sugar content and acidity, were evaluated over a week of ambient storage at 25oC and 52% RH. The results indicated that Josapine pineapples take about 11 days to progress from maturity stage 1 to stage 7. The moisture content of fruit increased from 93.5% wb to 95.1% wb over the 11 days period. Analysis on the color of the juice showed the color space coordinate parameter b varies between 9.11 to 15.8, parameter a increased from 3.33 to 3.68 and the 'L' value decreased from 39.46 to 38.7 at the initial ripening stage but increased to 40.9 in the later stages. The TSS increased at the early ripening stage but decreased toward the end of ripening period. Freezing point, water activity and pH of juice range were 2.77 to 2.90 oC, 0.988 to 0.997 and 3.81 to 4.10 respectively. The total sugar and acidity in juice range were 12.5 to 17% and 0.69 to 0.90% respectively. The TSS/acid ratio of juice range was 12.32 to 18.60. The data presented in this work demonstrate the relationship between physicochemical properties of Josapine pineapples and the ripening process.
Publisher: Elsevier BV
Date: 04-2018
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2013
End Date: 2016
Funder: Ministry of Higher Education, Malaysia
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